arXiv subjects

Zheng-Xin Yan

Publications and source records attributed to Zheng-Xin Yan.

4 recordsLinked to original sources

arXiv2021

Glauber Gluon Effects in Soft Collinear Factorization

Effects of Glauber gluons, which cause the elastic scattering process between different jets, are studied in the frame of soft-collinear effective theory(SCET). Glauber modes are added into the Lagrangian before integrated out, which is helpful in studies on Glauber couplings of collinear and soft particles explicitly. It is proved that interactions after the hard collision cancel out in processes inclusive enough. So are interactions with the light cone coordinates Sx^{+}$ and $x^{-}$ greater than those of the hard collision. Eikonalization of Glauber couplings of active particles and absorption of active-active and active-soft and active-spectator Glauber exchanges into soft and collinear Wilson lines are discussed, which is related to loop level definitions of Glauber gluons here. The active-spectator coherence are proved to be harmless on inclusive summation of spectator-spectator and spectator-soft Glauber exchanges. Based on this result, spectator-spectator and spectator-soft Glauber exchanges are proved to cancel out in processes considered here. Graphic aspects of the cancellation are also discussed to explain relations between the graphic cancellation of Glauber gluons in the frame of perturbative QCD and operator level skills in the paper.

hep-ph↗

arXiv2017

Equivalence Between the Gauge $n\cdot\partial n\cdot A=0$ and the Axial Gauge

Discontinuity of gauge theory in the gauge condition $n\cdot\partial n\cdot A=0$, which emerges at $n\cdot k=0$, is studied here. Such discontinuity is different from that one confronts in axial gauge and can not be regularized by conventional analytical continuation method. The Faddeev-Popov determinate of the gauge $n\cdot\partial n\cdot A=0$, which is solved explicitly in the manuscript, behaves like a $δ$-functional of gauge potentials once singularities in the functional integral is neglected and the length along $n^μ$ direction of the space tends to infinity. As a sequence, perturbation series in the gauge $n\cdot\partial n\cdot A=0$ returns to that in axial gauge for short-range correlated objects that are free from singularities in path integral. However, the equivalence between the gauge $n\cdot\partial n\cdot A=0$ and axil gauge is nontrivial for long-range correlated objects and quantities that are affected by singularities in path integral. Continuity of gauge links one encounter in perturbation theory and lattice calculation is affected by such discontinuity.

hep-th↗

arXiv2017

The Continuity of the Gauge Fixing Condition $n\cdot\partial n\cdot A=0$ for $SU(2)$ Gauge Theory

The continuity of the gauge fixing condition $n\cdot\partial n\cdot A=0$ for $SU(2)$ gauge theory on the manifold $R\bigotimes S^{1}\bigotimes S^{1}\bigotimes S^{1}$ is studied here, where $n^μ$ stands for directional vector along $x_{i}$-axis($i=1,2,3$). It is proved that the gauge fixing condition is continuous given that gauge potentials are differentiable with continuous derivatives on the manifold $R\bigotimes S^{1}\bigotimes S^{1}\bigotimes S^{1}$ which is compact.

physics.gen-ph↗

arXiv2017

Quantization of Yang-Mills Theories without the Gribov Ambiguity

A gauge condition is presented here to quantize non-Abelian gauge theory on the manifold $R\otimes S^{1}\otimes S^{1}\otimes S^{1}$, which is free from the Gribov ambiguity. Perturbative calculations in the new gauge behave like the axial gauge in ultraviolet region, while infrared behaviours of the perturbative series are quite nontrivial. The new gauge condition, which reads $n\cdot\partial n\cdot A=0$, may not satisfy the requirement that $A^μ(\infty)=0$ in conventional perturbative calculations. However, such contradiction is not harmful for gauge theories constructed on the manifold $R\otimes S^{1}\otimes S^{1}\otimes S^{1}$.

hep-th↗